Microscopic colitis refers to inflammation of the colon that is only visible when the colon's lining is examined under a microscope. The appearance of the inner colon lining in microscopic colitis is normal by visual inspection during colonoscopy or flexible sigmoidoscopy. The diagnosis of microscopic colitis is made when a doctor, while performing colonoscopy or flexible sigmoidoscopy, takes biopsies (small samples of tissue) of the normal-appearing lining, and then examines the biopsies under a microscope.
The primary symptom of microscopic colitis is chronic, watery diarrhea. Patients with microscopic colitis can have diarrhea for months or years before the diagnosis is made.
One study has implicated long term (longer than 6 months) use of nonsteroidal anti-inflammatory drugs (NSAIDs) as a cause of microscopic colitis. Some patients' diarrhea improves after stopping the NSAIDs.
The treatment of microscopic colitis has not been standardized because there have not been adequate large scale, prospective, placebo controlled treatment trials. The following strategies are safe and may relieve diarrhea in some patients:
- Avoid NSAIDs
- Trial of lactose elimination (just to eliminate the possibility that intolerance to lactose in milk is aggravating the diarrhea)
- Anti-diarrhea agents such as Imodium or Lomotil
- Bismuth subsalicylate such as Pepto-Bismol
- 5-ASA compounds such as Asacol, Pentasa, or Colazal
Two recent, controlled trials showed that budesonide (Entocort, a poorly absorbed steroid) is effective in controlling diarrhea in more than 75% of the patients with collagenous colitis, but the diarrhea tends to recur soon after stopping Entocort.
information courtesy of MedicineNet.com.